Question 1

What appliance costs the most to run?

Accepted Answer

By wattage: dryers (3,000–5,000W), electric water heaters (4,500W), and central AC (3,500W). By monthly cost: heating/cooling systems dominate because they run the most hours.

Question 2

Does wattage equal cost?

Accepted Answer

No. Cost = wattage × hours. A 3,000W dryer for 1 hour costs the same as a 125W TV running 24 hours. High wattage, low usage can cost less than low wattage, high usage.

Question 3

How do I find my appliance's wattage?

Accepted Answer

Check the label on the back or bottom — it lists watts (W) or amps (A). If amps, multiply by voltage (120V in US, 230V in UK) for watts. Or search '[appliance model] wattage'.

Question 4

Is it cheaper to run appliances at night?

Accepted Answer

Only if your utility offers time-of-use rates. Most residential customers pay the same rate 24/7. Check your bill — if you see 'peak' and 'off-peak' rates, then yes, running at night saves money.

Appliance Cost Comparison in Hawaii